The DNA contained in an organism and the mRNA transcribed from DNA, are very complex and small in amount. Therefore, amplification process is required for DNA analysis of the DNA sequence except few cases. Two kinds of techniques are generally used for this sequencing purpose.
In the first method, a DNA is selectively cloned in a microorganism or prepared to a library, and then after proliferation of the microorganism in a large scale, the microorganisms containing desired DNA fragments are isolated.
The second method is that desired DNA site is amplified by the Polymerase Chain Reaction (hereinafter, PCR). In the second method, however, there is a problem that the sequence of both ends of the desired DNA site should be noted in advance. Therefore, in case the base sequence of the DNA to be amplified has not yet been identified, the perfect amplification of full length DNA or cDNA of an organism through PCR process without missing any part thereof is impossible.
Generally, in order to analyze the base sequence of DNA in a large scale, a full length DNA of an organism is divided into several short fragments to be inserted into a vehicle for amplification, and then the base sequence of the DNA fragments thus amplified, are determined.
For this process, the ordered library is generally used. However, the ordered library technique is very difficult, complex, time-consuming and very laborious process, thus this process is the biggest obstacles for analyzing the DNA sequence.
Therefore, the object of the present invention is to provide a method for amplifying DNA without any information for the base sequence of the DNA to be amplified in advance.